// FILE: ./internal/sources/common/event.go
package common

import (
	"time"

	"gitea.maximumdirect.net/ejr/feedkit/event"
)

// SingleRawEvent constructs, validates, and returns a slice containing exactly one event.
//
// This removes repetitive "event envelope ceremony" from individual sources.
// Sources remain responsible for:
//   - fetching bytes (raw payload)
//   - choosing Schema (raw schema identifier)
//   - computing Event.ID and (optional) EffectiveAt
//
// emittedAt is explicit so callers can compute IDs using the same timestamp (or
// so tests can provide a stable value).
func SingleRawEvent(
	kind event.Kind,
	sourceName string,
	schema string,
	id string,
	emittedAt time.Time,
	effectiveAt *time.Time,
	payload any,
) ([]event.Event, error) {
	if emittedAt.IsZero() {
		emittedAt = time.Now().UTC()
	} else {
		emittedAt = emittedAt.UTC()
	}

	e := event.Event{
		ID:          id,
		Kind:        kind,
		Source:      sourceName,
		EmittedAt:   emittedAt,
		EffectiveAt: effectiveAt,

		// RAW schema (normalizer matches on this).
		Schema: schema,

		// Raw payload (usually json.RawMessage). Normalizer will decode and map to canonical model.
		Payload: payload,
	}

	if err := e.Validate(); err != nil {
		return nil, err
	}

	return []event.Event{e}, nil
}